University ranks helmets for safety: MIPS helmets come out on top

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When it comes to protection, are all bike helmets the same? And does MIPS actually work? A new helmet-safety rating program created by Virginia Tech and the Insurance Institute for Highway Safety (IIHS) answers these questions and awarded star ratings to 30 popular helmets.

In Virginia Tech’s testing, cost did not predict performance; the $200 Bontrager Ballista MIPS and the $75 Specialized Chamonix MIPS were among the four helmets that scored 5 stars. The $165 Lazer Genesis was one of two to get 2 stars, and the rest of the 30 models fell in the 3- to 4-star range.

“Our goal with these ratings is to give cyclists an evidence-based tool for making informed decisions about how to reduce their risk of injury,” says Steve Rowson, director of the Virginia Tech Helmet Lab and an associate professor of biomedical engineering and mechanics. “We also hope manufacturers will use the information to make improvements.”

30 helmets were given star ratings based on a battery of tests

How Virginia Tech tested

Current helmet safety tests vary by region. In the United States, the Consumer Product Safety Commission (CPSC) test requires that helmets prevent head impact accelerations over 300G — basically an impact that could crack a skull or cause severe brain injury.

In CPSC testing, a helmet with a weighted headform inside is dropped straight down onto an anvil. Virginia Tech — and many bike companies — point out that this test does not accurately represent most bike crashes, nor investigate how, if at all, a helmet can dissipate lower-force impacts.

To create its battery of tests, Virgina Tech researchers looked at real-world crashes. Joe Young, a spokesperson for the Insurance Institute for Highway Safety, explained the test to BikeRadar:

“All helmets were struck at six different points and at two different speeds at each point,” Young said. “The locations and speeds were determined based on studies of real bike crashes. Each location and speed is weighted differently based on predicted exposure and the concussion risk is computed as a function of linear acceleration and rotational velocity at each point.

Virginia Tech tested impacts at six locations – four in the CPSC-specified range and two down along the helmet’s edge

“The result is a single value for each helmet that predicts concussion risk. Five-star helmets are expected to reduce concussion risk by 70 percent or greater. A 4-star helmet is expected to reduce concussion risk 60–70 percent.”

At Virginia Tech, Rowson and his colleagues have been testing football and hockey helmets for years, as well as studying soccer headgear. The bike-helmet study was an extension of this work.

To quantify how much impact each helmet absorbed, Virginia Tech researchers used headforms with embedded accelerometers to measure linear acceleration and rotational velocity. From there, they estimated the risk of concussion.

Unlike the CPSC test that drops the helmet straight down, the Virginia Tech battery of tests involves rotating the helmet to test at various angles and speeds to replicate different types of common crashes

All four helmets that scored 5 stars had Multi-Directional Impact Protection System (MIPS), as did many of the 4-star helmets.

“The idea behind MIPS is that, when the helmet hits the road and sticks initially due to the high friction, your head actually slides relative to the helmet,” says Virginia Tech doctoral student Megan Bland, who did much of the research. Bland found that this slip plane did reduce rotational forces, and therefore the risk of concussion and other injuries.

Before settling on a test protocol, Virginia Tech researchers tried two formats with IIHS support. First, they used the Consumer Product Safety Commission (CPSC) rig and tested at the side of the helmet — within the CPSC test area — and at the front rim of the helmet, which isn’t subject to CPSC testing. On certain helmets, the rim location performed more poorly.

The second study used another test rig with a slanted anvil covered in sandpaper to replicate asphalt. The researchers felt this set-up better represented the angle at which a rider’s head often hits the ground in a crash. Further, this test rig produced greater differences among helmets. So a modified version of that rig was used for the ratings.

Virginia Tech sought to replicate real-world crashes with its tests, instead of just dropping a helmet straight down on an anvil, as the CPSC test requires

Bike helmet companies respond

POC head of product Oscar Huss said he would have to further evaluate the Virginia Tech methodology to give a full answer as to whether or not he agreed with the testing and its conclusions.

“It is not entirely clear if the chosen approximation (Rowson, S., Duma, S.M., et al. Rotational head kinematics in football impacts: an injury risk function for concussion. Annals of Biomedical Engineering, 2012. 40(1): p. 1-13) is the most relevant for cycling helmets,” Huss said. “We have seen many helmet testing methods prioritizing certain parameters which improves a certain solution and our approach has always been to combine different methodologies to consider as many aspects as possible.”

As to whether he liked the idea of a safety rating from a third party, Huss said POC supports “all initiatives aiming to improve safety and making it easier for the customer to choose a safer product.”

“But it is important that the methods chosen are unbiased and not chosen to prove one technology’s superiority or that the method chosen leads to helmets only performing well in those gives test methods, but rather in an overall sense,” he said. “For example, if everyone prioritized a 6.26 m/s drop in a few hit locations with the aim to achieve a 5-star rating, but forget about other velocities and locations/conditions, the customer could be misled instead of helped.”

In California, Giro has its own battery of helmet tests, ranging from the standard CPSC drop-on-an-anvil to angled impacts, a swinging torso that hits an angled surface and even a ‘sled’ test that simulates the ground speed of a cyclist.

Thom Parks, senior director of product safety at Giro’s parent company Vista, called Virginia Tech’s rating “another tool that can help us understand the performance of our products and the potential for helmets to reduce risk of traumatic brain injuries, including concussions.”

“The testing and ratings represent a single methodology based on Virginia Tech’s point of view and their available resources for testing cycling helmets,” Parks said. “And we believe the Cycling STAR ratings can be complimentary to the research and testing we do in the Dome as part of helmet creation at Giro.”

“We applaud Virginia Tech for applying a STAR rating system to cycling helmets,” he said. “We are also encouraged to see more research on cycling head protection, and to see our helmets perform well in the initial Virginia Tech tests. It is important to remember that every impact is a unique event. No rating system can prove if a specific helmet will or will not prevent, or even reduce the risk of concussion. This is why we encourage riders to choose a helmet that offers the most coverage that they’re willing to wear, that is designed to the most relevant standards for the riding they do, and to inspect and replace their helmet regularly.”

BikeRadar has also contacted Bontrager, Specialized and Lazer for comment, but has not immediately heard back. We will update this story as they respond.